Newly described plant is latest fruit of Sri Lankan botanists’ collaboration

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COLOMBO — The Knuckles mountain range in central Sri Lanka is a UNESCO-declared World Heritage Site that’s home to a rich diversity of wildflowers. Among them are plants in the genus Impatiens, a new member of which has just been described by Sri Lankan researchers in the journal Phytotaxa — and which is already considered critically endangered because of its fleeting rarity.

The road to the discovery began in 2016, when researchers Champika Bandara, a Ph.D. candidate at the University of Sri Jayawardenepura, and Sanath Bandara Herath of the Open University of Sri Lanka (OUSL), were exploring the plant life along the banks of a stream in the Dothalugala area of the Knuckles range. It was here where they first spotted a purple impatiens flower that neither had ever seen before.

Impatiens subcordata was considered a possibly extinct species in Sri Lanka’s 2012 red list, after not having been seen in more than a century, but was “rediscovered” in 2013 by the same team of researchers who would go on to describe I. jacobdevlasii. Image courtesy of Bhathiya Gopallawa.

Fast-forward three years later, and as Bandara and Herath were deepening their study into what they suspected was a species new to science, another researcher, Bhathiya Gopallawa, a Ph.D. candidate at the University of Peradeniya, also encountered the same flowering plant.

Gopallawa’s discovery, however, occurred on a different trail in the mountains, called Thangappuwa, about 20 kilometers (12 miles) from the earlier location.

Realizing that he was looking at an undescribed species, and aware that Bandara and Herath were also working on an unknown impatiens, Gopallawa reached out to the others to compare notes.

The study that emerged from their collaboration, published this April, describes a new species that the researchers named Impatiens jacobdevlasii, after Jacob de Vlas, a Dutch botanist best known for co-authoring the Illustrated field guide to the flowers of Sri Lanka with his wife, Johanna. Published in three volumes from 2008-2019, the guide lists more than 3,000 native and introduced flower plants found on the island.

“I learned a lot from de Vlas’s field guide and also received the opportunity to get personal guidance to be a field botanist,” Bandara told Mongabay. He added that the field guide was also invaluable to other young botanists across Sri Lanka.

The color variation of Impatiens jacobdevlasii flowers: White, light purple, light pink, and deep purple. Images courtesy of Bhathiya Gopallawa.

Newly described, but critically endangered

The new species is categorized as critically endangered in light of its low population, declining population trend, and limited distribution. Bandara said the Dothalugala population of I. jacobdevlasii has declined by 80% since that initial 2016 sighting.

The Dothalugala population is located near a stream along the Deanston–Dothalugala nature trail, and Thangappuwa population is found on wet, rocky surfaces along the Thangappuwa–Alugallena nature trail. Any road-clearing, weeding, construction or maintenance efforts by the authorities should prioritize the management and further conservation of this new species, Bandara said.

The discovery of the Thangappuwa population could potentially lead to more new plant species being described. That’s because Gopallawa’s survey there in 2019 was funded by the Hilltop Flora project and the recovery plan for another flowering plant, Osbeckia lanata, both administered by the Royal Botanical Gardens of Peradeniya.

“The flora on the montane forests is special and also heavily threatened, so we initiated this project to study the plants in several mountains in 2013, which still continues,” said Achala Attanayake, deputy director of the botanical gardens and a co-author of the I. jacobdevlasii paper. Attanayake added that several other important findings from the project are planned for release.

Dutch biologist Jacob de Vlas, after whom the newly described species is named, is co-author of the three-volume “Illustrated field guide to the flowers of Sri Lanka,” published from 2008-2019 documenting more than 3,000 native and introduced species on the island. Image courtesy of Bhathiya Gopallawa.

Global impatiens hotspot

The description of I. jacobdevlasii brings to 25 the number of known impatiens species found in Sri Lanka, 18 of them endemic. Most grow in wet forests near streams and wet rocky areas, and several are threatened because of their restricted range. Besides I. jacobdevlasii, two of the endemic species are categorized as critically endangered and nine as endangered under the 2021 National Red List. Another, not seen in 95 years, is considered possibly extinct.

“Sadly, one site located near a waterfall [known to host impatiens plants] was cleared for tourist activities, indicating the kind of threats these plants face,” Gopallawa told Mongabay.

Sri Lanka is considered one of six global hotspots for impatiens species, which number more than 1,000 worldwide. The other regions with a high diversity of these flowering plants are the eastern Himalayas, southern India, Southeast Asia, tropical Africa, and Madagascar.

The new species is categorized as critically endangered in light of its low population, declining population trend, and limited distribution. Image courtesy of Bhathiya Gopallawa.

Collaboration, not competition

The description of the new species also highlights growing interest by young Sri Lankan researchers in the field of botany, and the spirit of collaboration that drives it.

In many scientific fields around the world, competition for funding and publication clout often pits researchers against each other to be the first to announce a new discovery. But when Gopallawa reached out to Bandara and Herath about his find in 2019, there was no secrecy and it was a collaborative effort from the get-go, Gopallawa said.

“Both of the other researchers are my good friends and we do not compete among each other,” he said.

He added that the community of young botanists in Sri Lanka is a close-knit family and shares information about new findings, so that they can continue bringing new discoveries like this to the rest of the world.

That same spirit of collaboration was behind the “resurrection” of Impatiens subcordata, a species that hadn’t been seen in more than a century and was declared possibly extinct in the 2012 red list. Gopallawa, Bandara and Herath found the plant in the wild in 2013, and while they originally planned to include this rediscovery in their latest paper, they decided against it as the plant’s status had by then been updated in the 2021 red list and De Vlas’s field guide.

Sri Lanka is currently experiencing a resurgence in botanical studies, driven by dozens of young field researchers like Bandara, Herath and Gopallawa. Their hope is that working together to bring the richness of Sri Lanka’s plant life to light will inspire greater interest and discoveries in the field.

Citation:

Bandara, C., Herath, S. B., Gopallawa, B., & Attanayake, A. (2022). Impatiens jacobdevlasii (Balsaminaceae), a new species from Knuckles massif of Sri Lanka. Phytotaxa, 543(3), 181-187. doi: 10.11646/phytotaxa.543.3.2

Banner image of an Impatiens jacobdevlasii plant near a stream in the Dothalugala site along the Deanston–Dothalugala nature trail, courtesy of Sanath Bandara Herath.

This article was originally published on Mongabay